I absolutely love my Shark NeverChange Air Purifier MAX. It is very quiet. It is very sensitive. I can spray perfume or turn on a Scentsy burner in another room and it immediately can sense the smell in the air and goes to purifying.  At that point it doesn’t take very long before it cleans the air.  Every time I walk into my home my home smells clean. I highly recommend this air purification system.